Question

To begin with, I followed this tutorial:

http://www.codeproject.com/Articles/102065/Android-A-beginner-s-guide?fid=1583614&df=90&mpp=10&noise=1&prof=True&sort=Position&view=Expanded&spc=None&fr=11#xx0xx

I have checked a good many of the similar posts here, but all of the solutions have been code specific and haven’t worked.

I am just starting out developing android apps, and found this tutorial. When I launch it though, the emulator gives me the this app has stopped message. There are no warnings from my code, so I don’t even know where to begin.

Here’s my code:
MainActivity.java

package com.example.test;

import android.app.Activity;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;


public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.activity_main, menu);
    //return true;

//get the two controls we created earlier, also with the resource reference and the id
final TextView lv_View = (TextView)findViewById(R.id.lv_View);
lv_View.setText("4");
final EditText et_Text = (EditText)findViewById(R.id.et_Text);  

//add new KeyListener Callback (to record key input)
et_Text.setOnKeyListener(new View.OnKeyListener()
{
    //function to invoke when a key is pressed
    public boolean onKey(View v, int keyCode, KeyEvent event)
    {
        //check if there is 
        if (event.getAction() == KeyEvent.ACTION_DOWN)
        {
            //check if the right key was pressed
            if (keyCode == KeyEvent.KEYCODE_DPAD_CENTER)
            {
                                //add the text to the text view
                lv_View.setText(lv_View.getText() + ", " + 
                                 et_Text.getText());
                                //and clear the EditText control
                et_Text.setText("");
                return true;
            }
        }
        return false;
    }
});
return true;
} 
}

test manifest

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.test"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
    android:minSdkVersion="8"
    android:targetSdkVersion="15" />

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name="com.example.test.MainActivity"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

</manifest>

strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>

<string name="app_name">test</string>
<string name="hello_world">&quot;I got it to work!&quot;</string>
<string name="menu_settings">Settings</string>

</resources>

activity_main.xml (layout)

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity"
 >
 <edittext android:layout_height="wrap_content" 
         android:layout_width="fill_parent" android:textColor="#FF0000FF"
         android:id="@+id/et_Text" />
<textview android:layout_height="wrap_content" android:layout_width="fill_parent"
android:textColor="#FF00FF00" android:id="@+id/lv_View" />
<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:layout_centerVertical="true"
    android:textColor="#FF00FF00"
    android:text="@string/hello_world" 
    />

</RelativeLayout>

LogCat report

12-18 21:34:37.873: W/Trace(713): Unexpected value from nativeGetEnabledTags: 0
12-18 21:34:38.442: W/Trace(713): Unexpected value from nativeGetEnabledTags: 0
12-18 21:34:38.522: W/Trace(713): Unexpected value from nativeGetEnabledTags: 0
12-18 21:34:39.562: D/AndroidRuntime(713): Shutting down VM
12-18 21:34:39.602: W/dalvikvm(713): threadid=1: thread exiting with uncaught exception     (group=0x40a70930)
12-18 21:34:39.812: E/AndroidRuntime(713): FATAL EXCEPTION: main
12-18 21:34:39.812: E/AndroidRuntime(713): java.lang.RuntimeException: Unable to start     activity ComponentInfo{com.example.test/com.example.test.MainActivity}:     android.view.InflateException: Binary XML file line #7: Error inflating class edittext
12-18 21:34:39.812: E/AndroidRuntime(713):  at     android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
12-18 21:34:39.812: E/AndroidRuntime(713):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
12-18 21:34:39.812: E/AndroidRuntime(713):  at android.app.ActivityThread.access$600(ActivityThread.java:141)
12-18 21:34:39.812: E/AndroidRuntime(713):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
12-18 21:34:39.812: E/AndroidRuntime(713):  at android.os.Handler.dispatchMessage(Handler.java:99)
12-18 21:34:39.812: E/AndroidRuntime(713):  at android.os.Looper.loop(Looper.java:137)
12-18 21:34:39.812: E/AndroidRuntime(713):  at android.app.ActivityThread.main(ActivityThread.java:5039)
12-18 21:34:39.812: E/AndroidRuntime(713):  at java.lang.reflect.Method.invokeNative(Native Method)
12-18 21:34:39.812: E/AndroidRuntime(713):  at java.lang.reflect.Method.invoke(Method.java:511)
12-18 21:34:39.812: E/AndroidRuntime(713):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
12-18 21:34:39.812: E/AndroidRuntime(713):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
12-18 21:34:39.812: E/AndroidRuntime(713):  at dalvik.system.NativeStart.main(Native Method)
12-18 21:34:39.812: E/AndroidRuntime(713): Caused by: android.view.InflateException: Binary XML file line #7: Error inflating class edittext
12-18 21:34:39.812: E/AndroidRuntime(713):  at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:698)
12-18 21:34:39.812: E/AndroidRuntime(713):  at android.view.LayoutInflater.rInflate(LayoutInflater.java:746)
12-18 21:34:39.812: E/AndroidRuntime(713):  at android.view.LayoutInflater.inflate(LayoutInflater.java:489)
12-18 21:34:39.812: E/AndroidRuntime(713):  at android.view.LayoutInflater.inflate(LayoutInflater.java:396)
12-18 21:34:39.812: E/AndroidRuntime(713):  at android.view.LayoutInflater.inflate(LayoutInflater.java:352)
12-18 21:34:39.812: E/AndroidRuntime(713):  at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:270)
12-18 21:34:39.812: E/AndroidRuntime(713):  at android.app.Activity.setContentView(Activity.java:1881)
12-18 21:34:39.812: E/AndroidRuntime(713):  at com.example.test.MainActivity.onCreate(MainActivity.java:17)
12-18 21:34:39.812: E/AndroidRuntime(713):  at android.app.Activity.performCreate(Activity.java:5104)
12-18 21:34:39.812: E/AndroidRuntime(713):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
12-18 21:34:39.812: E/AndroidRuntime(713):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
12-18 21:34:39.812: E/AndroidRuntime(713):  ... 11 more
12-18 21:34:39.812: E/AndroidRuntime(713): Caused by: java.lang.ClassNotFoundException: Didn't find class "android.view.edittext" on path: /data/app/com.example.test-2.apk
12-18 21:34:39.812: E/AndroidRuntime(713):  at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:65)
12-18 21:34:39.812: E/AndroidRuntime(713):  at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
12-18 21:34:39.812: E/AndroidRuntime(713):  at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
12-18 21:34:39.812: E/AndroidRuntime(713):  at android.view.LayoutInflater.createView(LayoutInflater.java:552)
12-18 21:34:39.812: E/AndroidRuntime(713):  at android.view.LayoutInflater.onCreateView(LayoutInflater.java:643)
12-18 21:34:39.812: E/AndroidRuntime(713):  at com.android.internal.policy.impl.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:66)
12-18 21:34:39.812: E/AndroidRuntime(713):  at android.view.LayoutInflater.onCreateView(LayoutInflater.java:660)
12-18 21:34:39.812: E/AndroidRuntime(713):  at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:685)
12-18 21:34:39.812: E/AndroidRuntime(713):  ... 21 more

Thanks for any help! If you need any more information, just let me know. I’m still not sure of what’s needed to trouble shoot these kinds of errors.

Answer 1

In your layout XML file, you need to ensure that textview and edittext are CamelCase otherwise android will not know how to inflate the layout. This is because the android layout inflater attempts to instance a class by using the name specifed in the XML file. In this case, android.view.TextView and android.view.EditText.

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <EditText android:layout_height="wrap_content" 
         android:layout_width="fill_parent"
         android:textColor="#FF0000FF"
         android:id="@+id/et_Text" />

    <TextView android:layout_height="wrap_content"
         android:layout_width="fill_parent"
         android:textColor="#FF00FF00"
         android:id="@+id/lv_View" />

    <TextView
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_centerHorizontal="true"
         android:layout_centerVertical="true"
         android:textColor="#FF00FF00"
         android:text="@string/hello_world" />

</RelativeLayout>